package com.product_customer;

/*线程之间的通信问题：生产者和消费者问题 ！ 等待唤醒，通知唤醒
* 线程交替执行  A   B  操作同一个变量   num=0
* A  num+1
* B  num-1
* */
public class A {
    public static void main(String[] args) {
        Data data = new Data();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.methodadd();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.methodreduce();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.methodreduce();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"C").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.methodadd();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }

}

//判断等待，业务，通知
class Data{//数字、资源,只要是并发编程就一定要加锁

    private int number = 0;

    //method +1  -1
    public synchronized void methodadd() throws InterruptedException {
        while (number!=0){
            //等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程，+1完毕，通知其他线程唤醒
        this.notifyAll();
    }

    public synchronized void methodreduce() throws InterruptedException {
        while (number==0){
            //等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程，-1完毕
        this.notifyAll();
    }
}
